error: Multiple top-level packages discovered in a flat-layout

$ python3 -m build
* Creating venv isolated environment...
* Installing packages in isolated environment... (setuptools >= 40.8.0, wheel)
* Getting build dependencies for sdist...
error: Multiple top-level packages discovered in a flat-layout: ['api', 'log', 'data', 'files', 'config', 'deploy', 'alembic', 'fixtures', 'modeling', 'frontend', 'specialistoff'].

To avoid accidental inclusion of unwanted files or directories,
setuptools will not proceed with this build.

If you are trying to create a single distribution with multiple packages
on purpose, you should not rely on automatic discovery.
Instead, consider the following options:

1. set up custom discovery (`find` directive with `include` or `exclude`)
2. use a `src-layout`
3. explicitly set `py_modules` or `packages` with a list of names

To find more information, look for "package discovery" on setuptools docs.

ERROR Backend subprocess exited when trying to invoke get_requires_for_build_sdist